Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Iowa’s caseload jumped more than 200 in the past week, though some of the increase consisted of older cases that had been stuck in a backlog of paperwork, the Iowa Department of Public Health said Tuesday.

The epidemic has hit nine states. Nebraska has reported 110 mumps cases. Cases have also been reported in Kansas, Illinois, Indiana, Michigan, Missouri, Wisconsin and Minnesota.

It is the nation’s biggest mumps epidemic since 269 cases were reported in Kansas in 1988-89, according to the national Centers for Disease Control and Prevention.

Mumps is a virus that is spread by coughing and sneezing. It typically causes fever, headaches and swollen glands under the jaw. But it can lead to deafness, meningitis and damage to the testicles.